Millimeter wave hand tracking

ABSTRACT

A system includes a locatable glove and a pose determination device. The locatable glove includes a glove body worn over a hand of a user, and a plurality of positioning transponders. The positioning transponders are coupled to the glove body at various positions on the glove body, and each re-radiates a received signal, the re-radiated signal unique to the positioning transponder. The pose determination device includes a plurality of antennas and a controller. The antennas are each configured to receive the unique signals re-radiated by the positioning transponders. The antennas are physically separated from each other. The controller is communicatively coupled to the plurality of antennas, and is configured to determine, for each of the received unique signals, a location of the position on the locatable glove of the positioning transponder corresponding to the unique signal.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of co-pending U.S. application Ser.No. 15/874,761, filed Jan. 18, 2018, which is incorporated by referencein its entirety.

BACKGROUND

The present disclosure generally relates to hand tracking, andspecifically relates to tracking the position of a hand using a gloveequipped with millimeter-wave transponders.

Hand tracking refers to the process of determining the location orposition of a user's hand. Hand tracking for virtual reality and/oraugmented reality applications is emerging as an important feature.Current hand-tracking systems rely in inertial motion tracking oroptical motion capture. Inertial motion tracking involves placinginertial sensors on a glove, and using the inertial sensors to trackrotations and determine hand movement or pose. Inertial motion trackingdoes not capture the position of the hand in space and may drift overtime, and materials in the environment can interfere with the functionof the inertial sensors. Optical motion capture involves tracking usingone or more cameras to capture images of the hand, and determining theposition and pose of the hand from the images. In some cases, the userwears a glove with markers that are tracked. Optical motion capturerequires the markers on the user's hand to be in the line of sight ofthe camera. Further, markers that are not visually distinct from eachother can lead to inaccurate hand tracking, especially if a smallproportion of the markers is visible to the camera.

SUMMARY

A system for tracking the position and movement of a locatable garmentworn by a user is disclosed herein. For example, the locatable garmentmay be a glove that is worn by the user and used to track a user's hand.The system includes a pose determination device, external to thelocatable garment, to determine the position of the garment, whichcorresponds to the position of a body part (e.g., a hand) inside thelocatable garment (e.g., a glove). The locatable garment includesmultiple positioning transponders, such as millimeter-wave transponders,located in different positions on the locatable garment. The posedetermination device includes multiple antennas. At least one of theantennas interrogates the locatable garment's positioning transponders,which re-radiate signals received from the interrogating antenna. Basedon the signals re-radiated from the positioning transponders andreceived at the multiple antennas, the pose determination device cantriangulate a position of each of the positioning transponders. Eachpositioning transponder has at least one unique transmissioncharacteristic, such as a frequency band, a phase state, a modulatedcode, or a time at which the antenna re-radiates, which allow the posedetermination device to distinguish the individual positioningtransponders. Based on the determined location of each positioningtransponder, the pose determination device can determine the position ofthe locatable garment, which corresponds to the position of the user'sbody or body part. As used herein, the position of a locatable garmentcan include one or more of the position of the glove in space (e.g.,relative to the location of another device worn by the user, such as anHMD including a pose determination device, and/or relative to thelocation of a device at a fixed location and in the vicinity of thelocatable garment, such as a console including a pose determinationdevice), the pose of the body or body part (based on the positions ofpoints on the locatable garment relative to each other), and theorientation of the body part (e.g., relative to another part of theuser's body, or relative to a fixed location in the vicinity of thelocatable garment).

In some embodiments, a system including a locatable glove and a posedetermination device is described herein. The locatable glove includes aglove body that can be worn over a hand of a user. A plurality ofpositioning transponders are coupled to the glove body at acorresponding plurality of positions on the glove body. Each positioningtransponder is configured to re-radiate a received signal, there-radiated signal being unique to the positioning transponder. The posedetermination device includes a plurality of antennas and a controllercommunicatively coupled to the plurality of antennas. The antennas arephysically separated from each other, and they are each configured toreceive the unique signals re-radiated by the plurality of positioningtransponders. The controller is configured to determine, for each of thereceived unique signals, a location of the position on the locatableglove of the positioning transponder corresponding to the unique signal.

In some embodiments, a locatable glove is described herein. Thelocatable glove includes a glove body configured to be worn over atleast a portion of a hand of a user, and a plurality of transponderscoupled to the glove body at a corresponding plurality of positions onthe glove body. Each transponder is configured to re-radiate a receivedsignal, the re-radiated signal unique to the transponder and in amillimeter-wave band. The locatable glove also includes a controllerthat is communicatively coupled to the plurality of transponders. Thecontroller is configured to control emission of the plurality oftransponders.

In some embodiments, a pose determination device is disclosed herein.The pose determination device includes a plurality of antennas and acontroller communicatively coupled to the antennas. The antennas arephysically separated from each other on the pose determination device.Each antenna is configured to receive a plurality of signalscorresponding to a plurality of unique signals re-radiated by acorresponding plurality of positioning transponders on a locatableglove. The controller receives, from each antenna, the plurality ofsignals received by the antenna. The controller identifies, for eachpositioning transponder of the plurality of positioning transponders, aset of received signals corresponding to the positioning transponderbased on a characteristic of the signals in the set of received signals.Each received signal in the set was received by a corresponding one ofthe plurality of antennas. The controller determines, for eachpositioning transponder of the plurality of positioning transponders, alocation of the position on the locatable glove of the positioningtransponder. Based on the determined locations, the controllerdetermines a position of the locatable glove.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a system environment, in accordance with anembodiment.

FIG. 2 illustrates a plan view of a locatable glove with positioningtransponders, in accordance with an embodiment.

FIG. 3 illustrates a plan view of a locatable glove with positioningtransponders controlled by switches, in accordance with an embodiment.

FIG. 4 shows a locatable glove with positioning transponders and a posedetermination device receiving signals from the positioningtransponders, in accordance with an embodiment.

FIG. 5 is a flow chart showing a process for determining the pose of auser's hand, in accordance with an embodiment.

The figures depict embodiments of the present disclosure for purposes ofillustration only. One skilled in the art will readily recognize fromthe following description that alternative embodiments of the structuresand methods illustrated herein may be employed without departing fromthe principles, or benefits touted, of the disclosure described herein.

DETAILED DESCRIPTION

Embodiments of the invention may include or be implemented inconjunction with an artificial reality system. Artificial reality is aform of reality that has been adjusted in some manner beforepresentation to a user, which may include, e.g., a virtual reality (VR),an augmented reality (AR), a mixed reality (MR), a hybrid reality, orsome combination and/or derivatives thereof. Artificial reality contentmay include completely generated content or generated content combinedwith captured (e.g., real-world) content. The artificial reality contentmay include video, audio, haptic feedback, or some combination thereof,and any of which may be presented in a single channel or in multiplechannels (such as stereo video that produces a three-dimensional effectto the viewer). Additionally, in some embodiments, artificial realitymay also be associated with applications, products, accessories,services, or some combination thereof, that are used to, e.g., createcontent in an artificial reality and/or are otherwise used in (e.g.,perform activities in) an artificial reality. The artificial realitysystem that provides the artificial reality content may be implementedon various platforms, including a head-mounted display (HMD) connectedto a host computer system, a standalone HMD, a mobile device orcomputing system, or any other hardware platform capable of providingartificial reality content to one or more viewers.

In artificial reality systems, hand tracking and gesture recognition canbe used for user input. For example, the artificial reality system canrecognize known gestures and respond accordingly. If a haptic glove isused, the artificial reality system can also provide haptic feedback tothe user. For example, if a user makes a gesture that corresponds topicking up an object, a haptic tracking glove can track the user'smotion, such as reaching and grasping, and provide tactile feedback sothat the user senses an object is in his hand. As described herein, theartificial reality system can use signals re-radiated by transponders ona locatable glove, such as a haptic glove, to determine the location ofthe glove. The re-radiated signals may differ in at least onecharacteristic, so that the artificial reality system can identify thesignals from each individual positioning transponder and determine eachindividual positioning transponder's position. This allows more accuratedetermination of a hand position compared to prior techniques. Thetransponders may re-radiate signals in a millimeter-wave band. Theextremely high frequency (EHF) band, as designated by the InternationalTelecommunication Union (ITU) encompasses frequencies from 30 GHzthrough 300 GHz, and wavelengths between 1 mm and 1 cm. Radio waves inor near this band are commonly referred to as millimeter-waves, or asbeing in the millimeter-wave band. In some embodiments, the antennas mayemit and receive waves having wavelengths outside the EHF band, such asany wavelength or band in the ultra high frequency (UHF) band (1 meterto 1 decimeter), super high frequency (SHF) band (1 dm to 1 cm), orterahertz band (100 μm to 1 mm). In some embodiments, the signals may bereceived even if the positioning transponders are not in the direct lineof sight of an interrogating antenna, e.g., through a garment or throughfabric of the glove. At some wavelengths, the signals may able travelthough objects or though the user's body, e.g., through the user's hand.

FIG. 1 is a block diagram of a system environment 100 in which alocatable garment 140 operates. The system environment 100 may be, forexample, an artificial reality system. In some embodiments, the systemenvironment 100 is capable of alternating between operating as a VR, anMR, and an AR system, or some subset thereof. The system environment 100shown in FIG. 1 comprises a head-mounted display (HMD) 110 and alocatable garment 140 that are both coupled to a console 170. While FIG.1 shows an example system environment 100 including one HMD 110 and onelocatable garment 140, in other embodiments any number of thesecomponents may be included in the system environment 100. For example,the system environment 100 may include two locatable garments 140 (e.g.,one glove for each hand) that are worn by the same user. As anotherexample, the system environment 100 may include multiple locatablegarments 140 intended to be worn by multiple users, with each locatablegarment 140 or each pair of locatable garments 140 associated with adifferent HMD 110. In alternative configurations, different oradditional components may be included in the system environment 100.

The HMD 110 is a head-mounted display that presents media to a user.Examples of media presented by the HMD 110 include images, video, audio,or some combination thereof. In some embodiments, audio is presented viaan external device (e.g., speakers or headphones) that receives audioinformation from the HMD 110, the console 170, or both, and presentsaudio data based on the audio information. In some embodiments, the HMD110 may also act as an AR and/or MR headset. In these embodiments, theHMD 110 augments views of a physical, real-world environment withcomputer-generated elements (e.g., images, video, sound, etc.).

The HMD 110 includes an electronic display 112, sensors 114, and acommunication interface 116. Some embodiments of the HMD 110 havedifferent components than those described here. Similarly, the functionscan be distributed among the components in a different manner than isdescribed here.

The electronic display 112 displays images to the user in accordancewith data received from the console 170. In various embodiments, theelectronic display 112 may comprise a single electronic display 112 ormultiple electronic displays 112 (e.g., one display for each eye of auser).

The sensors 114 include one or more hardware devices that detect spatialand motion information about the HMD 110. Spatial and motion informationcan include information about the position, orientation, velocity,rotation, and acceleration of the HMD 110. For example, the sensors 114may include a gyroscope that detects rotation of the user's head whilethe user is wearing the HMD 110. This rotation information can then beused (e.g., by the engine 174) to adjust the images displayed on theelectronic display 112.

The communication interface 116 enables input and output to the console170. In some embodiments, the communication interface 116 is a bus, suchas High-Definition Multimedia Interface (HDMI), Universal Serial Bus(USB), Video Graphics Array (VGA), Digital Visual Interface (DVI),DisplayPort™, or some combination thereof. In other embodiments, thecommunication interface 116 includes several distinct communicationbuses operating together or independently. In one embodiment, thecommunication interface 116 includes wireless connections for sendingdata collected by the sensors 114 from the HMD 110 to the console 170but also includes a wired connection (e.g., an HDMI or DVI connection)that receives audio/visual data to be rendered on the electronic display112.

The locatable garment 140 is a trackable wearable device. The locatablegarment 140 may be configured to be worn on a portion of a user's body,such as the user's hand (e.g., a glove). In other embodiments, thelocatable garment 140 is configured to be worn on another part of theuser's body, such as an arm, a leg, or a foot, or worn on multiple partsof the user's body, such as a shirt, pants, or body suit. The locatablegarment 140 may collect information about the portion of the user's bodythat can be used as input for virtual reality applications 172 executingon the console 170. The locatable garment 140 includes a haptic feedbackmechanism 142, auxiliary sensors 144, a communication interface 146, andpositioning transponders 148. Some embodiments of the locatable garment140 have different components than those described here, e.g., thelocatable garment 140 may include additional components that are notshown in FIG. 1, such as a power source (e.g., an integrated battery, aconnection to an external power source, or some combination thereof) andone or more controllers (e.g., for controlling the positioningtransponders). Similarly, the functions can be distributed among thecomponents in a different manner than is described here.

The haptic feedback mechanism 142 provides haptic feedback to the userby directing the portion of the user's body to move in a particular wayor in a particular direction or preventing the portion of the user'sbody from moving in certain directions or in certain ways. The hapticfeedback mechanism 142 may include actuators for applying forces onportions of the user's body. By applying forces to the user's body, thehaptic feedback mechanism 142 may move a portion of the user's bodyapply torque to a joint of a user's body, or produce tactile sensationfor the user.

The auxiliary sensors 144 include one or more hardware devices thatdetect spatial information for the locatable garment 140. Examples ofauxiliary sensors 144 include: one or more accelerometers, one or moregyroscopes, one or more magnetometers, another suitable type of sensorthat detects motion, a type of sensor used for error correction, or somecombination thereof. The auxiliary sensors 144 may provide data to aninertial measurement unit (IMU), which is an electronic device thatgenerates data indicating a position of the locatable garment 140 basedon measurement signals received from one or more of the auxiliarysensors 144. The auxiliary sensors 144 may be located external to theIMU, internal to the IMU, or some combination thereof.

The spatial information detected by the auxiliary sensors 144 and/or IMUmay include information about position, orientation, velocity, rotation,and acceleration, or some combination thereof. The spatial informationmay refer to the entire locatable garment 140, subdivisions of thelocatable garment 140, or both. For example, if the locatable garment140 is a haptic glove, auxiliary sensors 144 may identify positions andorientations of various portions of the glove, such as glove digits orportions of the glove digits corresponding to a wearer's fingertips orknuckles. The auxiliary sensors 144 may also detect forces applied bythe user to the locatable garment 140. The spatial information maysupplement position information determined using the positioningtransponders 148.

The communication interface 146 enables input from and output to theconsole 170 and/or HMD 110. In some embodiments, the communicationinterface 146 may be a single communication bus, such as USB. In otherembodiments, the communication interface 146 includes several distinctcommunication buses operating together or independently. For example,the communication interface 146 may include separate communication busesfor receiving control signals for the haptic feedback mechanism 142 andsending data from the auxiliary sensors 144 to the console 170 or HMD110. The one or more communication buses of the communication interface146 may be implemented as wired connections, wireless connections, orsome combination thereof.

The positioning transponders 148 are transponders that receivere-radiate signals that can be used to track the locatable garment 140.For example, the positioning transponders 148 may re-radiate signals inthe millimeter-wave band. The positioning transponders 148 may eachinclude a receiving antenna and a transmitting antenna. The positioningtransponders 148 may be active, passive, semi-active, or semi-passivetransponders. The positioning transponders 148 may be located at knownlocations on the locatable garment 140; for example, if the locatablegarment 140 is a glove, it may have positioning transponders 148 nearthe fingertips, at on one or more locations along each finger (e.g., onor near one or more knuckles), at one or more locations on the palm ofthe glove, and at one or more locations on the back of the glove. Eachpositioning transponder 148 may re-radiate a unique signal so that eachpositioning transponder 148 can be uniquely identified.

The console 170 is a computing device that executes artificial realityapplications. For example, the console 170 processes input data from thesensors 114 on the HMD 110 and the positioning transponders 148 on thelocatable garment 140 and, based on the input, provides output data forthe electronic display 112 on the HMD 110 and the haptic feedbackmechanism 142 on the locatable garment 140. In some embodiments, theconsole 170 also processes input data from the auxiliary sensors 144 onthe locatable garment 140. The console 170, or portions thereof, may beintegrated with the HMD 110, the locatable garment 140, or both the HMD110 and the locatable garment 140. For example, in some embodiments, theHMD 110 includes the console 170 in its entirety. The console 170 can beimplemented as any kind of computing device, such as an integratedsystem-on-a-chip, a microcontroller, a desktop or laptop computer, aserver computer, part of a HMD, a tablet, a smart phone, or other mobiledevice. Thus, the console 170 may include components common to typicalcomputing devices, such as a processor, random access memory (RAM), astorage device, a network interface, an I/O interface, and the like.

The processor may be or include one or more graphics processing units(GPUs), microprocessors, or application specific integrated circuits(ASICs). The memory may be or include RAM, ROM, DRAM, SRAM, and MRAM,and may include firmware, such as static data or fixed instructions,BIOS, system functions, configuration data, and other routines usedduring the operation of the computing device and the processor. Thememory also provides a storage area for data and instructions associatedwith applications and data handled by the processor.

The storage device provides non-volatile, bulk, or long term storage ofdata or instructions in the computing device. The storage device maytake the form of a magnetic or solid state disk, tape, CD, DVD, or otherreasonably high capacity addressable or serial storage medium. Multiplestorage devices may be provided or be available to the computing device.Some of these storage devices may be external to the computing device,such as network storage or cloud-based storage. The network interfaceincludes an interface to a network and can be implemented as either awired or wireless interface. The I/O interface interfaces the processorto peripherals (not shown) such as, depending upon the computing device,sensors, displays, cameras, color sensors, microphones, keyboards andUSB devices.

In the example shown in FIG. 1, the console 170 further includesapplications 172, an engine 174, antennas 176, and a locatable garmentpose module 178. An application 172 running on the engine 174 maygenerate an artificial reality environment. In some embodiments, theapplications 172, the engine 174, and the locatable garment pose module178 are implemented as software modules that are stored on the storagedevice and executed by the processor. Some embodiments of the console170 include additional or different components than those described inconjunction with FIG. 1. Similarly, the functions further describedbelow may be distributed among components of the console 170 in adifferent manner than is described here.

Each application 172 is a group of instructions that, when executed by aprocessor, generates virtual reality content for presentation to theuser. An application 172 may generate content (e.g., artificial realitycontent) in response to inputs received from the user via movement ofthe HMD 110 or the locatable garment 140. Examples of applications 172include gaming applications, conferencing applications, video playbackapplications, augmented reality application, telerobotic applications,or other suitable applications.

The antennas 176 transmit signals to the positioning transponders 148 onthe locatable garment 140 and receive signals transmitted by thepositioning transponders 148. For example, the antennas 176 may be radarantennas that interrogate the positioning transponders 148, whichre-radiate the interrogation signals transmitted by the antennas 176.The antennas 176 receive the re-radiated signals, which can identify thepositioning transponder from which they came and provide a rangingmeasurement. The antennas 176 may be configured to emit and detectelectromagnetic radiation in the frequency band of the positioningtransponders 148, e.g., the millimeter-wave band. In some embodiments,each antenna 176 may include a transmitting antenna and a separatereceiving antenna. In some embodiments, each antenna 176 is an antennaarray, or a single antenna array is used. The antennas 176 may bedistributed at different locations on the console 170 so that thesignals they receive differ based on the antennas' locations, whichallows triangulation or trilateration of the positioning transponders'positions. In some embodiments, one or more antennas 176 are housedseparately from the console 170 and are in wireless or wiredcommunication with the console 170. In some embodiments, some or all ofthe antennas 176 are integrated into the HMD 110.

The antennas 176 transmit the received signals to the locatable garmentpose module 178, which processes the signals. In some embodiments, eachpositioning transponder 148 re-radiates a signal with a uniquecharacteristic, and the locatable garment pose module 178 identifies thesignals received by the antennas 176 from each positioning transponder148. The locatable garment pose module 178 determines a range to eachpositioning transponder. If the antennas 176 are distributed atdifferent locations within the console 170, or different locationsoutside the console 170 (e.g., at different locations on the HMD 110),the locatable garment pose module 178 can triangulate the position ofeach positioning transponder 148 based on the range measurements. Basedon the positions of the positioning transponders 148, the locatablegarment pose module 178 can determine the overall position (includingone or more of location, orientation, and pose) of the locatable garment140. In embodiments in which the antennas 176 are integrated into theHMD 110, the locatable garment pose module 178 may also be integratedinto the HMD.

The engine 174 is a software module that allows the applications 172 tooperate in conjunction with the HMD 110 and the locatable garment 140.In some embodiments, the engine 174 receives information from sensors114 on the HMD 110 and provides the information to an application 172.Based on the received information, the engine 174 determines mediacontent to provide to the HMD 110 for presentation to the user via theelectronic display 112 or haptic feedback to provide to the locatablegarment 140 to provide to the user via the haptic feedback mechanism.For example, if the engine 174 receives information from the sensors 114on the HMD 110 indicating that the user has looked to the left, theengine 174 generates content for the HMD 110 that mirrors the user'smovement in a virtual environment.

In some embodiments, the engine 174 receives position information fromthe locatable garment pose module 178 and/or the auxiliary sensors 144and provides the information to an application 172. The application 172can use the information to perform an action within the virtual world ofthe application 172. For example, if the engine 174 receives informationfrom the locatable garment pose module 178 that the user has closed herfingers around a position corresponding to a virtual coffee mug in avirtual environment and raised her hand, a simulated hand in theapplication 172 picks up the virtual coffee mug and lifts it to acorresponding height.

The engine 174 may also provide feedback to the user that the action wasperformed. The provided feedback may be visual via the electronicdisplay 112 in the HMD 110 (e.g., displaying the simulated hand as itpicks up and lifts the virtual coffee mug) or haptic feedback via thehaptic feedback mechanism 142 in the locatable garment 140 (e.g.,resisting movement of a user's fingers from curling past a certain pointto simulate the sensation of touching a solid coffee mug). The hapticfeedback may also be force feedback from some machine being controlledby the user.

FIG. 2 illustrates a plan view of a locatable glove 200 (also referredto as glove 200) with positioning transponders, in accordance with anembodiment. In some embodiments, the locatable glove 200 is anembodiment of the locatable garment 140. The glove 200 includes one ormore positioning transponders 210A-210H and a controller 220. Inaddition to being locatable, the glove 200 may provide haptic feedback,as described with respect to FIG. 1. In the embodiment of FIG. 2, theglove 200 includes a glove body that has five glove digits (one for eachfinger and the thumb), and each of the five glove digits has arespective positioning transponder 210A-210E near the fingertip. Theglove 200 has several additional positioning transponders 210F-210H on aportion corresponding to the back of the hand. In alternate embodiments(not shown), the glove body may include some lessor number of glovedigits. For example the glove body may include a glove digit for a thumband index finger, but not other fingers. In FIG. 2, the glove 200 isshown in an orientation corresponding to posterior view of a user'sright hand (i.e., a plan view of the back of the user's hand). The glove200 may also have positioning transponders on the underside of the glove200, corresponding to the palm of the user's hand, and one or more sidesof the glove 200. Any configuration of positioning transponders on theglove 200 may be used; for example, the glove 200 may have multiplepositioning transponders on each glove digit, e.g., one transponder ateach bend location (e.g., located proximate to a knuckle) of a glovedigit. In some embodiments, multiple antennas (e.g., multiple antennasof a single transponder) may be configured to operate together. Forexample, the multiple antennas may operate together to control directionof signals they emit (e.g., operate as a phased array).

When the positioning transponders 210A-210H receive an interrogationsignal from an antenna, e.g., one of antennas 176, the positioningtransponders 210A-210H re-radiate the received signal. In someembodiments, each positioning transponders re-radiates signals that areunique from the other positioning transponders 210A-210H, as describedin more detail below, so that the interrogating device (e.g., theconsole 170) can distinguish the positioning transponders 210A-210H. Thepositioning transponders 210A-210H are configured to re-radiate signalsat a particular wavelength or band of wavelengths. For example, thepositioning transponders 210A-210H may re-radiate signals in themillimeter-wave band, described above, or a neighboring frequency band.

The positioning transponders 210A-210H are controlled by the controller220. The controller 220 is in communication with the positioningtransponders 210-210H, e.g., through wires integrated into the glove 200(not shown in FIG. 2). The glove 200 may have a communication interface,such as communication interface 146 described with respect to FIG. 1,integrated into the controller 220 or in communication with thecontroller 220. The controller 220 may receive and process instructions,e.g., from console 170, for controlling the positioning transponders210A-210H. The controller 220 can instruct the positioning transponders210A-210H to re-radiate signals, and in some embodiments, controls oneor more properties of the positioning transponders 210A-210H so thatthey re-radiate unique signals that can be individually identified by areceiving device, such as the console 170.

For example, the positioning transponders 210A-210H can bedifferentiated based on the time at which they are configured tore-radiate signals, the wavelength or band of wavelengths of theirre-radiated signals, a code in the re-radiated signals, a combination ofthese characteristics, or some other signal property or combination ofproperties. In one example, the controller 220 instructs eachpositioning transponder 210A-210H to re-radiate in a given order, e.g.,positioning transponder 210A, then 210B, then 210C, and so forth. Onlythe positioning transponder set to re-radiate at a particular time is onand able to re-radiate; the other positioning transponders are off orconfigured not to re-radiate interrogation signals. If a receivingdevice knows the order in which the positioning transponders 210A-210Hare configured to re-radiate signals, the receiving device can identifythe positioning transponder 210A-210H corresponding to each signal basedon the time at which the signal was received. In some embodiments, thetransmission times may be coordinated with a second glove, and in somecases additional gloves, so that the different gloves can be identified.

As another example, the controller 220 instructs each positioningtransponder 210A-210H to re-radiate a signal with a specified wavelengthor band, e.g., positioning transponder 210A at 1-1.01 mm, 210B at1.10-1.11 mm, 210C at 1.20-1.21 mm, and so forth. To do so, eachpositioning transponder may shift the frequency of the interrogatingsignal by a different amount when it re-radiates the signal. If areceiving device knows the wavelengths or bands at which eachpositioning transponders 210A-210H is set to re-radiate, the receivingdevice can identify the positioning transponder 210A-210H correspondingto each signal based on the wavelength or band. In some embodiments, thewavelengths or bands may be coordinated with a second glove, and in somecases additional gloves, so that the different gloves can be identified.

As another example, the controller 220 instructs each positioningtransponder 210A-210H to re-radiate a signal with a code (e.g., amodulated code) that can be used to identify the positioning transponder210A-210H. The code for a positioning transponder 210A-210H can includean identification of its position on the glove 200. A receiving deviceprogrammed to interpret the code can identify the positioningtransponder 210A-210H corresponding to each signal. In some embodiments,the code also provides other information about the glove 200, such asthe size of the glove 200 (if gloves are available in different sizes),whether the glove 200 is a right-hand glove or left-hand glove, and anidentifier of the glove 200 or a user of the glove (e.g., if multiplegloves are being tracked).

Any other technique or combination of techniques for positioning signalsfrom multiple antennas or multiple transponders such that thetransponders can be distinguished may be used. As other examples,polarization, amplitude, and/or phase state of the signals re-radiatedby the positioning transponders 210A-210H may differ between thepositioning transponders.

The positioning transponders 210A-210H may be divided into transmittinggroups. For example, the positioning transponders 210A-210H may bedivided into two groups, the first group including positioningtransponders 210A-210D, and the second group including positioningtransponders 210E-210H. The first group of transponders may allre-radiate signals at a first time, at four different wavelengths orbands, and the second group re-radiate signals at a second time, reusingthe same four wavelengths or bands. A receiving device can thendistinguish the signals based on their wavelength or bands and the timeat which they are received. In particular, the receiving device may beinformed that positioning transponders 210A-210D re-radiates first,followed by positioning transponders 210E-210H. Between successive setsof transmissions, controller 220 may insert a time gap betweentransmission by positioning transponders 210E-210H and transmission bypositioning transponders 210A-210D, so that the receiving device knowsthat the pattern will begin again, starting with positioningtransponders 210A-210D.

In some embodiments, the positioning transponders 210A-210H or subgroupsof the positioning transponders 210A-210H are configured to transmit orre-radiate as one or more phased arrays. A phrased array is a set ofantennas that can be electronically steered to point in a particulardirection, e.g., towards a receiving device. To steer the beam, thecontroller 220 instructs the positioning transponders 210A-210H tore-radiate signals that have a particular phase relationship so that there-radiated waves add together to increase the radiation in thedirection of a receiving device. The controller 220 may receive feedbackfrom the interrogating device, such as the console 170, instructing thecontroller 220 on the most recent orientation of the glove 220 relativeto the receiving device. The controller 220 can use this information todetermine a direction to steer the phased array formed by positioningtransponders 210A-210H such that it directed towards the interrogatingdevice. In some embodiments, the glove 200 has integrated sensors, suchas auxiliary sensors 144, that provide data to the controller 220 thatthe controller 220 can use to determine the direction to direct thephased array. The data from the auxiliary sensors 144 may includeinformation describing the orientations and relative locations of thepositioning transponders 210A-210H, or any changes to the orientationsand relative locations since the most recent orientation was receivedfrom the receiving device.

In some embodiments, the controller 220 instructs one or a subset of thepositioning transponders 210-210H to be operational based on conditionsof the glove 200 or a particular use case. For example, based on themost recent orientation of the glove 200, only a subset of thepositioning transponders 210A-210H may be useful for determining theposition of the glove 200, e.g., if other positioning transponders arenot within range of the interrogating device. As another example, if thelocation of the glove 200 within the room is used for a particularapplication, and not the orientation or pose of the glove 200, a singlepositioning transponder could be used. As a third example, if thelocation and/or orientation of the glove 200 are used for a particularapplication, but not the pose of the glove 200, a subset of thepositioning transponders could be used, e.g., one transponder on thethumb and one on the pinky, or one transponder on the back of the handand one on the palm.

FIG. 3 illustrates a plan view of a locatable glove 300 with positioningtransponders controlled by switches, in accordance with an embodiment.The glove 300 includes positioning transponders 310A-310E and acontroller 320, which are similar to the positioning transponders210A-210E and controller 220 described with respect to FIG. 2. The glove300 also includes links 330A-330E connecting the controller 320 torespective positioning transponders 310A-310E, and switches 340A-340Efor controlling the connections of the links 330A-330E to thepositioning transponders 310A-310E. While the glove 300 includes onlyfive positioning transponders 310A-310E for illustrative purposes, itshould be understood that the glove 300 can include additionalpositioning transponders at other locations, as described with respectto FIG. 2. These additional positioning transponders can be connected tothe controller 320 by links and switches.

Links 330A-330E may be wires for transmitting power to the positioningtransponders 310A-310E from a power source via the controller 320. Thelinks 330A-330E may also transmit signals from the controller 320 to thepositioning transponders 310A-310E, e.g., instructions to re-radiate thereceived signal with a particular wavelength, code, or othercharacteristic. The links 330A-330E may also transmit signals from thepositioning transponders 310A-310E to the controller 320, such asoperational or status information. The links 330A-330E may be integratedinto the glove 330 so that they are not visible to a user.

The switches 340A-340E can be operated by the controller 320 to connectand disconnect the positioning transponders 310A-310E from the links330A-330E. In particular, if the glove 300 is configured to transmitsignals from different positioning transponders 310A-310E at differentpoints of time, the controller 320 can close a switch on a positioningtransponder at a time that it should re-radiate, and open the switch onthe transmitting a signal when another positioning transponder isre-radiating. As shown in FIG. 3, switch 340A, connecting link 330A topositioning transponder 310A, is closed. Thus, positioning transponder310A is re-radiating a signal. Switches 340B-340E are open, so none ofpositioning transponders 310B-310E are re-radiating. As described above,in some embodiments, multiple positioning transponders re-radiatesimultaneously, so the controller 320 may instruct two or more switches340A-340E to close simultaneously.

FIG. 4 shows a locatable glove 400 with positioning transponders and apose determination device 440 receiving signals from the positioningtransponders, in accordance with an embodiment. The locatable glove 400may be an embodiment of the locatable gloves 200 or 300, described withrespect to FIGS. 2 and 3. For simplicity, the locatable glove 400includes only two positioning transponders 410A and 410B. However, itshould be understood that the locatable glove 400 may include additionalpositioning transponders. The locatable glove 400 has a controller 420,which may operate in a similar manner to controllers 220 and 320described with respect to FIGS. 2 and 3. Moreover, it should beunderstood that while FIG. 4 illustrates a glove 400, in otherembodiments, the positioning transponders 410A and 410B may be on someother type of wearable locatable garment.

As shown in FIG. 4, each positioning transponder 410A and 410B on thelocatable glove 400 is re-radiating a respective signal 430A and 430B inthe direction of the pose determination device 440. The signals 430A and430B each have a unique characteristic or unique combinations ofcharacteristics, as described above, so that the pose determinationdevice 440 can distinguish signal 430A from signal 430B. The posedetermination device 440 may be an embodiment of the console 170described with respect to FIG. 1. For example, in some instances thepose determination device 440 is a HMD that includes some or all of thefunctionality of the console 170. The pose determination device 440includes three antennas 450A, 450B, and 450C. One of the antennas450A-450C transmits an interrogating signal to the locatable glove 400,which the positioning transponders 410A and 410B re-radiated as signals430A and 430B. The antennas 450A-450C are embodiments of the antennas176 described with respect to FIG. 1. One or more antennas 450A-450C maybe located outside the pose determination device 440 and transmit datato the pose determination device 440. In some embodiments, more thanthree antennas 450A-450C are included, or an antenna array is usedrather than three individual antennas 450A-450C.

Each antenna 450A-450C receives both signals 430A and 430B. The posedetermination device 440 (e.g., the console 170 having a locatablegarment pose module 178) identifies received signals that werere-radiated from the same positioning transponder. For example, eachantenna 450A, 450B, and 450C receives signal 430A from positioningtransponder 410A. The pose determination device 440 groups these threereceived signals together as one subset of received signals, andtriangulates the location of positioning transponder 410A based on thethree versions of signal 430A in the subset. Similarly, the posedetermination device 440 groups together three versions of signal 430Breceived by antennas 450A, 450B, and 450C into a second subset ofsignals and triangulates the location of positioning transponder 410Bbased on this second subset.

The pose determination device 440 may compare the received signals 430Aand 430B to data describing which positioning transponder 410A-410Bcorresponds to which unique signal characteristic(s). Thus, the posedetermination device 440 can determine that signal 430A was re-radiatedby a positioning transponder 410A near the tip of the thumb of the glove400, and that signal 430B was re-radiated by a positioning transponder410B near the tip of the pinky finger of the glove 400. In otherembodiments, the pose determination device 440 does not have dataindicating which signal corresponds to which antenna, but can determinehow the received signals 430A and 430B correspond to different points onthe glove 400 based on the relative locations of the received signals430A and 430B.

In some embodiments, the positioning transponders 410A and 410B can beconfigured according to instructions from the pose determination device440. For example, if the pose determination device 440 is in range ofmultiple gloves, the pose determination device 440 may instruct theglove 400 to alter its re-radiated signals so that the posedetermination device 440 can distinguish the glove 400 from the otherglove(s). The pose determination device 440 can generate instructions tomodify an emission property of the positioning transponders 410A and410B, e.g., so that they re-radiate at a different frequency band ordifferent code, or different time. The controller 420 receives therequest to modify the signal properties of positioning transponders 410Aand 410B, and responsive to the request, the controller 420 instructsthe positioning transponders 410A and 410B to re-radiate signalsaccording the modified properties.

FIG. 5 is a flow chart showing a process 500 for determining the pose ofa user's hand, in accordance with an embodiment. The process 500 may beperformed by a pose determination device 440, such as a console 170having a locatable garment pose module 178. Other entities (e.g., a HMD110) may perform some or all of the steps in the process in otherembodiments. For example, antennas receiving signals from thepositioning transponders may be located on the HMD 110, or may bedistributed throughout a space, including in the console 170, in the HMD110, and/or on separate devices. A processor implementing the locatablegarment pose module 178 for determining a pose may be integrated intothe HMD 110, the console 170, the locatable garment 140, or any otherdevice. Embodiments may include different and/or additional steps, orperform the steps in different orders.

Multiple receivers, such as antennas 440A-440C or antennas 176, receive510 millimeter-wave band signals from positioning transponders on aglove. The signals may be re-radiated by positioning transponders on aglove, such as glove 200, 300, or 400 described with respect to FIGS.2-4, or by any other locatable garment 140. The multiple receivers aredistributed in space so that the location of each positioningtransponder can be determined by triangulation or trilateration.

The locatable garment pose module 178 determines 520 which receivedsignals were re-radiated from each positioning transponder based onunique signal characteristics. As described above with respect to FIG.2, each signal transmitted by a different positioning transponder on theglove has a unique characteristic or set of characteristics, and thelocatable garment pose module 178 can determine which received signalswere re-radiated by the same positioning transponder, and group signalsfrom the same positioning transponder into subsets. In some embodiments,the locatable garment pose module 178 can determine which particularglove location a received signal corresponds to, as described withrespect to FIG. 4.

The locatable garment pose module 178 triangulates 530 the locations ofthe positioning transponders using the respective received signals foreach positioning transponder. In particular, for each set of receivedsignals received from a single positioning transponder, the locatablegarment pose module 178 calculates the locations of the positioningtransponder based on the received signal using known triangulationtechniques.

The locatable garment pose module 178 determines 540 the pose of theuser's hand based on the locations of the positioning transponder. Thelocatable garment pose module 178 may interpolate the full hand posebased on the determined points on the hand. For example, if thelocatable garment pose module 178 references data indicating whichsignal corresponds to which positioning transponder, the locatablegarment pose module 178 may use this data to determine the pose of theuser's hand. In other embodiments, the locatable garment pose module 178may be able to determine the pose of the user's hand without such data,based on the relative locations of the positioning transponders.

The locatable garment pose module 178 may compare the determined pose toa database of known gestures to identify a gesture made by the user. Insome embodiments, the locatable garment pose module 178 may track thepose of the glove over time to identify gestures or other movements. Insome embodiments, the console 170 and/or HMD 110 may provide visualfeedback to the user in response to a gesture or movement, as describedwith respect to FIG. 1. In some embodiments, the glove provides hapticfeedback to the user, as described with respect to FIG. 1.

Additional Configuration Information

The foregoing description of the embodiments of the disclosure has beenpresented for the purpose of illustration; it is not intended to beexhaustive or to limit the disclosure to the precise forms disclosed.Persons skilled in the relevant art can appreciate that manymodifications and variations are possible in light of the abovedisclosure.

Some portions of this description describe the embodiments of thedisclosure in terms of algorithms and symbolic representations ofoperations on information. These algorithmic descriptions andrepresentations are commonly used by those skilled in the dataprocessing arts to convey the substance of their work effectively toothers skilled in the art. These operations, while describedfunctionally, computationally, or logically, are understood to beimplemented by computer programs or equivalent electrical circuits,microcode, or the like. Furthermore, it has also proven convenient attimes, to refer to these arrangements of operations as modules, withoutloss of generality. The described operations and their associatedmodules may be embodied in software, firmware, hardware, or anycombinations thereof.

Any of the steps, operations, or processes described herein may beperformed or implemented with one or more hardware or software modules,alone or in combination with other devices. In one embodiment, asoftware module is implemented with a computer program productcomprising a computer-readable medium containing computer program code,which can be executed by a computer processor for performing any or allof the steps, operations, or processes described.

Embodiments of the disclosure may also relate to an apparatus forperforming the operations herein. This apparatus may be speciallyconstructed for the required purposes, and/or it may comprise ageneral-purpose computing device selectively activated or reconfiguredby a computer program stored in the computer. Such a computer programmay be stored in a non-transitory, tangible computer readable storagemedium, or any type of media suitable for storing electronicinstructions, which may be coupled to a computer system bus.Furthermore, any computing systems referred to in the specification mayinclude a single processor or may be architectures employing multipleprocessor designs for increased computing capability.

Embodiments of the disclosure may also relate to a product that isproduced by a computing process described herein. Such a product maycomprise information resulting from a computing process, where theinformation is stored on a non-transitory, tangible computer readablestorage medium and may include any embodiment of a computer programproduct or other data combination described herein.

Finally, the language used in the specification has been principallyselected for readability and instructional purposes, and it may not havebeen selected to delineate or circumscribe the inventive subject matter.It is therefore intended that the scope of the disclosure be limited notby this detailed description, but rather by any claims that issue on anapplication based hereon. Accordingly, the disclosure of the embodimentsis intended to be illustrative, but not limiting, of the scope of thedisclosure, which is set forth in the following claims.

What is claimed is:
 1. A locatable garment comprising: one or more positioning transponders that are coupled to the locatable garment; and a controller that is coupled to the locatable garment, the controller configured to instruct at least one positioning transponder of the one or more positioning transponders to re-radiate a received signal such that the re-radiated signal is unique to the at least one positioning transponder, wherein a pose determination device is configured to determine a location of the at least one positioning transponder based in part on the re-radiated signal.
 2. The locatable garment of claim 1, wherein the controller is configured to instruct each of the one or more positioning transponders to re-radiate a signal within a different band within a millimeter-wave band.
 3. The locatable garment of claim 1, wherein the controller is configured to instruct each of the one or more positioning transponders to re-radiate a signal at a unique time relative to other positioning transponders.
 4. The locatable garment of claim 1, wherein the controller is configured to instruct each of the one or more positioning transponders to re-radiate a signal with a code that is different from other signals with codes re-radiated by other positioning transponders.
 5. The locatable garment of claim 1, wherein the locatable garment is a glove.
 6. The locatable garment of claim 5, wherein the one or more positioning transponders includes a first positioning transponder and a second positioning transponder, and the first positioning transponder is located proximate to a first fingertip of a first glove digit of the glove, and the second positioning transponder is located proximate to a second fingertip of a second glove digit of the glove.
 7. The locatable garment of claim 5, wherein the one or more positioning transponders includes a first group of positioning transponders and a second group of positioning transponders, and the controller is configured to instruct the first group of positioning transponders to all re-radiate respective signals at a first time and in different respective bands, and to instruct the second group of positioning transponders to all re-radiate respective signals at a second time and using the different respective bands.
 8. The locatable garment of claim 5, wherein the pose determination device is further configured to determine, based in part on the determined location of the position of the at least one positioning transponder on the glove, a position of a user's hand.
 9. The locatable garment of claim 1, wherein the one or more positioning transponders includes a plurality of positioning transponders, and the controller is further configured to instruct at least a portion of the plurality of positioning transponders to function as a phased array and re-radiate a signal in a direction of the pose determination device.
 10. The locatable garment of claim 1, wherein the pose determination device comprises at least one of a head-mounted display (HMD) and a console.
 11. A system comprising: a locatable garment comprising: one or more positioning transponders that are coupled to the locatable garment, a controller that is coupled to the locatable garment, the controller configured to instruct at least one positioning transponder of the one or more positioning transponders to re-radiate a received signal such that the re-radiated signal is unique to the at least one positioning transponder; and a pose determination device is configured to determine a location of the at least one positioning transponder based in part on the re-radiated signal.
 12. The system of claim 11, wherein the pose determination device includes one or more antennas each configured to receive signals re-radiated by the one or more positioning transponders.
 13. The system of claim 11, wherein the locatable garment is a glove.
 14. The system of claim 13, wherein the pose determination device is further configured to determine, based in part on the determined location of the position of the at least one positioning transponder on the glove, a position of a user's hand.
 15. The system of claim 11, wherein the pose determination device comprises at least one of a head-mounted display (HMD) and a console.
 16. A pose determination device comprising: a plurality of receiving antennas physically separated from each other on the pose determination device, each receiving antenna configured to receive a plurality of signals corresponding to a plurality of unique signals re-radiated by a corresponding plurality of positioning transponders on a locatable garment; and a processor communicatively coupled to the plurality of receiving antennas, the processor configured to: receive, from each receiving antenna, the plurality of signals received by the receiving antenna; identify, for each positioning transponder of the plurality of positioning transponders, a set of received signals corresponding to the positioning transponder based on a characteristic of the signals in the set of received signals, each received signal in the set was received by a corresponding one of the plurality of receiving antennas; determine, for each positioning transponder of the plurality of positioning transponders, a location of the position on the locatable garment of the positioning transponder; and determine, based on the locations, a position of the locatable garment.
 17. The pose determination device of claim 16, wherein the processor is configured to triangulate the location of the positioning transponder based on the identified set of the received signals.
 18. The pose determination device of claim 16, wherein the processor is further configured to identify, for each positioning transponder of the plurality of positioning transponders, the set of received signals corresponding to the positioning transponder based on one of a time at which the set of received signals were transmitted, a frequency of the set of received signals, and a code of the set of received signals.
 19. The pose determination device of claim 16, further comprising a memory for storing data describing, for each positioning transponder of the plurality of positioning transponders, a characteristic of the signal associated with the positioning transponder and a corresponding position on the locatable garment associated with the positioning transponder.
 20. The pose determination device of claim 16, wherein the processor is further configured to: determine a second position of the locatable garment; and identify, based on the position of the locatable garment and the second position of the locatable garment, a type of motion of a body part of a user wearing the locatable garment. 